一.ExcelUtil工具类
package com.gdz.excel.util;
import java.io.*;
import java.lang.reflect.Field;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.*;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.streaming.SXSSFSheet;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import javax.servlet.http.HttpServletResponse;
/**
* Excel导入导出
* @Author: guandezhi
* @Date: 2019/3/9 9:47
*/
public class ExcelUtil {
/**
* 导出多个sheet的excel
* @param name
* @param mapList
* @param response
* @param <T>
*/
public static <T> void exportMultisheetExcel(String name, List<Map> mapList, HttpServletResponse response) {
BufferedOutputStream bos = null;
try {
String fileName = name + ".xlsx";
bos = getBufferedOutputStream(fileName, response);
doExport(mapList, bos);
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (bos != null) {
bos.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 从excel中读内容
* @param filePath
* @param sheetIndex
* @return
*/
public static List<Map<String, String>> readExcel(String filePath, Integer sheetIndex) {
List<Map<String, String>> dataList = new ArrayList<>();
Workbook wb = ExcelUtil.createWorkBook(filePath);
if (wb != null) {
Sheet sheet = wb.getSheetAt(sheetIndex);
int maxRownum = sheet.getPhysicalNumberOfRows();
Row firstRow = sheet.getRow(0);
int maxColnum = firstRow.getPhysicalNumberOfCells();
String columns[] = new String[maxColnum];
for (int i = 0; i < maxRownum; i++) {
Map<String, String> map = null;
if (i > 0) {
map = new LinkedHashMap<>();
firstRow = sheet.getRow(i);
}
if (firstRow != null) {
String cellData = null;
for (int j = 0; j < maxColnum; j++) {
cellData = (String) ExcelUtil.getCellFormatValue(firstRow.getCell(j));
if (i == 0) {
columns[j] = cellData;
} else {
map.put(columns[j], cellData);
}
}
} else {
break;
}
if (i > 0) {
dataList.add(map);
}
}
}
return dataList;
}
private static BufferedOutputStream getBufferedOutputStream(String fileName, HttpServletResponse response) throws Exception {
response.setContentType("application/x-msdownload");
response.setHeader("Content-Disposition", "attachment;filename="
+ new String(fileName.getBytes("gb2312"), "ISO8859-1"));
return new BufferedOutputStream(response.getOutputStream());
}
private static <T> void doExport(List<Map> mapList, OutputStream outputStream) {
int maxBuff = 100;
// 创建excel工作文本，100表示默认允许保存在内存中的行数
SXSSFWorkbook wb = new SXSSFWorkbook(maxBuff);
try {
for (int i = 0; i < mapList.size(); i++) {
Map map = mapList.get(i);
String[] headers = (String[]) map.get("headers");
Collection<T> dataList = (Collection<T>) map.get("dataList");
String fileName = (String) map.get("fileName");
createSheet(wb, null, headers, dataList, fileName, maxBuff);
}
if (outputStream != null) {
wb.write(outputStream);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
private static <T> void createSheet(SXSSFWorkbook wb, String[] exportFields, String[] headers, Collection<T> dataList, String fileName, int maxBuff) throws NoSuchFieldException, IllegalAccessException, IOException {
Sheet sh = wb.createSheet(fileName);
CellStyle style = wb.createCellStyle();
CellStyle style2 = wb.createCellStyle();
//创建表头
Font font = wb.createFont();
font.setFontName("微软雅黑");
font.setFontHeightInPoints((short) 11);//设置字体大小
style.setFont(font);//选择需要用到的字体格式
style.setFillForegroundColor(HSSFColor.YELLOW.index);// 设置背景色
style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 居中
style.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
style.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
style2.setFont(font);//选择需要用到的字体格式
style2.setFillForegroundColor(HSSFColor.WHITE.index);// 设置背景色
style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); //垂直居中
style2.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 水平向下居中
style2.setBorderBottom(HSSFCellStyle.BORDER_THIN); //下边框
style2.setBorderRight(HSSFCellStyle.BORDER_THIN);//右边框
style2.setBorderLeft(HSSFCellStyle.BORDER_THIN);//左边框
style2.setBorderTop(HSSFCellStyle.BORDER_THIN);//上边框
Row headerRow = sh.createRow(0); //表头
int headerSize = headers.length;
for (int cellnum = 0; cellnum < headerSize; cellnum++) {
Cell cell = headerRow.createCell(cellnum);
cell.setCellStyle(style);
sh.setColumnWidth(cellnum, 4000);
cell.setCellValue(headers[cellnum]);
}
int rownum = 0;
Iterator<T> iterator = dataList.iterator();
while (iterator.hasNext()) {
T data = iterator.next();
Row row = sh.createRow(rownum + 1);
Field[] fields = getExportFields(data.getClass(), exportFields);
for (int cellnum = 0; cellnum < headerSize; cellnum++) {
Cell cell = row.createCell(cellnum);
cell.setCellStyle(style2);
Field field = fields[cellnum];
setData(field, data, field.getName(), cell);
}
rownum = sh.getLastRowNum();
// 大数据量时将之前的数据保存到硬盘
if (rownum % maxBuff == 0) {
((SXSSFSheet) sh).flushRows(maxBuff); // 超过100行后将之前的数据刷新到硬盘
}
}
}
private static <T> void doExport(String[] headers, String[] exportFields, Collection<T> dataList,
String fileName, OutputStream outputStream) {
int maxBuff = 100;
// 创建excel工作文本，100表示默认允许保存在内存中的行数
SXSSFWorkbook wb = new SXSSFWorkbook(maxBuff);
try {
createSheet(wb, exportFields, headers, dataList, fileName, maxBuff);
if (outputStream != null) {
wb.write(outputStream);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
/**
* 获取单条数据的属性
*
* @param object
* @param property
* @param <T>
* @return
* @throws NoSuchFieldException
* @throws IllegalAccessException
*/
private static <T> Field getDataField(T object, String property) throws NoSuchFieldException, IllegalAccessException {
Field dataField;
if (property.contains(".")) {
String p = property.substring(0, property.indexOf("."));
dataField = object.getClass().getDeclaredField(p);
return dataField;
} else {
dataField = object.getClass().getDeclaredField(property);
}
return dataField;
}
private static Field[] getExportFields(Class<?> targetClass, String[] exportFieldNames) {
Field[] fields = null;
if (exportFieldNames == null || exportFieldNames.length < 1) {
fields = targetClass.getDeclaredFields();
} else {
fields = new Field[exportFieldNames.length];
for (int i = 0; i < exportFieldNames.length; i++) {
try {
fields[i] = targetClass.getDeclaredField(exportFieldNames[i]);
} catch (Exception e) {
try {
fields[i] = targetClass.getSuperclass().getDeclaredField(exportFieldNames[i]);
} catch (Exception e1) {
throw new IllegalArgumentException("无法获取导出字段", e);
}
}
}
}
return fields;
}
/**
* 根据属性设置对应的属性值
*
* @param dataField 属性
* @param object 数据对象
* @param property 表头的属性映射
* @param cell 单元格
* @param <T>
* @return
* @throws IllegalAccessException
* @throws NoSuchFieldException
*/
private static <T> void setData(Field dataField, T object, String property, Cell cell)
throws IllegalAccessException, NoSuchFieldException {
dataField.setAccessible(true); //允许访问private属性
Object val = dataField.get(object); //获取属性值
Sheet sh = cell.getSheet(); //获取excel工作区
CellStyle style = cell.getCellStyle(); //获取单元格样式
int cellnum = cell.getColumnIndex();
if (val != null) {
if (dataField.getType().toString().endsWith("String")) {
cell.setCellValue((String) val);
} else if (dataField.getType().toString().endsWith("Integer") || dataField.getType().toString().endsWith("int")) {
cell.setCellValue((Integer) val);
} else if (dataField.getType().toString().endsWith("Long") || dataField.getType().toString().endsWith("long")) {
cell.setCellValue(val.toString());
} else if (dataField.getType().toString().endsWith("Double") || dataField.getType().toString().endsWith("double")) {
cell.setCellValue((Double) val);
} else if (dataField.getType().toString().endsWith("Date")) {
DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
cell.setCellValue(format.format((Date) val));
} else if (dataField.getType().toString().endsWith("List")) {
List list1 = (List) val;
int size = list1.size();
for (int i = 0; i < size; i++) {
//加1是因为要去掉点号
int start = property.indexOf(dataField.getName()) + dataField.getName().length() + 1;
String tempProperty = property.substring(start, property.length());
Field field = getDataField(list1.get(i), tempProperty);
Cell tempCell = cell;
if (i > 0) {
int rowNum = cell.getRowIndex() + i;
Row row = sh.getRow(rowNum);
if (row == null) {//另起一行
row = sh.createRow(rowNum);
//合并之前的空白单元格（在这里需要在header中按照顺序把list类型的字段放到最后，方便显示和合并单元格）
for (int j = 0; j < cell.getColumnIndex(); j++) {
sh.addMergedRegion(new CellRangeAddress(cell.getRowIndex(), cell.getRowIndex() + size - 1, j, j));
Cell c = row.createCell(j);
c.setCellStyle(style);
}
}
tempCell = row.createCell(cellnum);
tempCell.setCellStyle(style);
}
//递归传参到单元格并获取偏移量（这里获取到的偏移量都是第二层后list的偏移量）
setData(field, list1.get(i), tempProperty, tempCell);
}
} else {
if (property.contains(".")) {
String p = property.substring(property.indexOf(".") + 1, property.length());
Field field = getDataField(val, p);
setData(field, val, p, cell);
} else {
cell.setCellValue(val.toString());
}
}
}
}
private static Workbook createWorkBook(String filePath) {
Workbook wb = null;
if (filePath == null) {
return null;
}
String extString = filePath.substring(filePath.lastIndexOf("."));
InputStream is = null;
try {
is = new FileInputStream(filePath);
if (".xls".equals(extString)) {
return wb = new HSSFWorkbook(is);
} else if (".xlsx".equals(extString)) {
return wb = new XSSFWorkbook(is);
} else {
return wb;
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return wb;
}
/**
* 将字段转为相应的格式
* @param cell
* @return
*/
private static Object getCellFormatValue(Cell cell) {
Object cellValue = null;
if (cell != null) {
//判断cell类型
switch (cell.getCellType()) {
case Cell.CELL_TYPE_NUMERIC: {
cellValue = String.valueOf(cell.getNumericCellValue());
break;
}
case Cell.CELL_TYPE_FORMULA: {
if (DateUtil.isCellDateFormatted(cell)) {
cellValue = cell.getDateCellValue();////转换为日期格式YYYY-mm-dd
} else {
cellValue = String.valueOf(cell.getNumericCellValue()); //数字
}
break;
}
case Cell.CELL_TYPE_STRING: {
cellValue = cell.getRichStringCellValue().getString();
break;
}
default:
cellValue = "";
}
} else {
cellValue = "";
}
return cellValue;
}
}
二.测试一下
/**
* @Author: guandezhi
* @Date: 2019/3/9 11:18
*/
@Slf4j
@RestController
@RequestMapping("/excel")
public class ExcelController {
@RequestMapping(value = "/exportExcel")
public String exportExcel(HttpServletResponse response) throws Exception {
String[] headers = {"姓名", "性别", "年龄", "学校", "班级"};
String fileName = "学生表";
List<Student> studentList = new ArrayList<>();
Student student = new Student();
student.setStudentName("guandezhi");
student.setGrade("三年二班");
student.setAge(20);
student.setSchool("XX大学");
student.setSex("男");
studentList.add(student);
Map<String, Object> studentMap = new HashMap();
studentMap.put("headers", headers);
studentMap.put("dataList", studentList);
studentMap.put("fileName", fileName);
List<Map> mapList = new ArrayList();
mapList.add(studentMap);
ExcelUtil.exportMultisheetExcel(fileName, mapList, response);
return "success";
}
@RequestMapping(value = "/readExcel")
public String readExcel() throws Exception {
String filePath = "F:\student.xls";
List<Map<String, String>> mapList = ExcelUtil.readExcel(filePath, 0);
log.info("mapList:" + mapList);
return "success";
}
}
一.ExcelUtil工具类
package com.gdz.excel.util;
import
阅读背景：
Excel导入导出工具类（完整版）
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